Current engine designs emphasize compactness with the goal of achieving smaller size and lower weight. One drawback of this emphasis on engine compactness includes the difficulty associated with servicing an engine that has its valving, fuel systems and wiring very tightly packed under the valve cover. In particular, servicing a fuel injector of an engine in compact engine designs may be difficult due to problems accessing the components that secure the fuel injector in place. For example, the compactness of an engine may require the fuel injector clamp and fuel injector to be removed and installed simultaneously as one unit, or may require the removal of several other components of the engine in order to gain access to the injector clamp or the fuel injector itself.
In addition to the above stated accessibility problems, conventional injector clamping assemblies may also allow detrimental excess clamping loads to be applied to the fuel injector. Such detrimental excess loads could result from merely bolting down an injector clamp too tightly. Excess clamping loads applied to a fuel injector can distort the injector body which can cause seizure of the injector plunger or other close tolerance elements of the injector. Excess clamping loads may also prohibit the necessary expansion of the fuel injector due to combustion pressures and temperature variations.
One example of a conventional fuel injector clamping assembly is disclosed in U.S. Pat. No. 5,499,612 to Haughney et al. As illustrated in FIGS. 1-3 of Haughney et al., removal of the fuel injector from the cylinder head requires gaining access to an injector clamp fastener that is located in a narrow space between rocker arm members and located at a distance from the longitudinal axis of the fuel injector. In addition to gaining access to and disconnecting the injector clamp, removal of the fuel injector from the cylinder head also requires disconnecting a high pressure actuating fluid rail branch passage from the top of the fuel injector.
Haughney et al. rigidly clamps the fuel injector into the injector bore of the cylinder head by way of an injector clamp that is bolted to the cylinder head. If the injector clamp is bolted down too tightly to the cylinder head, detrimental clamping loads may be applied to the fuel injector.
The present invention provides a fuel injector clamping assembly that avoids some or all of the aforesaid shortcomings in the prior art.